Grinder pumps are often used in low pressure sewage systems for pumping sewage. A grinder pump is typically disposed in a sewage tank in which the grinder pump includes a motor for driving a grinder mechanism for cutting or grinding solids or semisolid matter in the sewage and a pump for pumping the processed sewage. Grinding solids and/or semisolid matter in the sewage allows the resulting particulate effluent to be transferred using a pump through relatively small diameter pipes without clogging.
Grinder pump systems are typically equipped with level sensors and a controller and an alarm. When the sewage reaches a certain level in the tank, the pump is automatically switched on and when the sewage in the tank falls below a certain level, the pump is automatically turned off. If the level rises too high, typically another sensor activates an alarm. Conventional level sensors include, for example, mechanical float switches, sensing tubes connected to pressure transducers, ultrasonic transducers, and capacitive level sensors.
There is a need for improved motors and particularly to motors such as grinder pumps having cut-out devices for protecting the motor or other associated equipment.